In a mobile communication system employing a code division multiple access (CDMA) scheme, various communication services using a high-speed data communication function, for example, 1×EV-DO (1× evolution-data only) has been provided. As an example of the communication service of 1×EV-DO, there is BCMCS (Broadcast and/or Multicast Services) transmitted to a plurality of wireless communication apparatus (for example, wireless communication terminals, wireless communication apparatus connected to a car navigation system, card modules and the like) simultaneously using a communication channel (see “CDMA2000 High rate Broadcast Packet Data Air Interface Specification (C.S0054-0 Version 1.0)-Section 1.4: Broadcast Channels”, 3GPP2, February 2004).
As an example of the conventional art of the BCMCS, there is BCMCS of CDMA2000, which is an efficient data transmission scheme for users in a wide range within an 1×EV-DO communication area. Moreover, in the BCMCS of CDMA2000, a robust error correction code is added, and there is no retransmission control.
As BCMCS applications, it is performed to distribute BCMCS contents of large amount of data at late night, early morning, or a predetermined night time at which a communication traffic amount is significantly decreased, and it is also performed to timely distribute data in order to display local information or the like in a telop form. FIG. 4 is a time chart illustrating a basic operation for receiving BCMCS in the conventional art. As shown in FIG. 4, a base station (access network) AN transmits BCMCS periodically. A terminal (access terminal) AT previously registers a desired program in BCMCS, or acquires a BCMCS program table through unicast.
The terminal AT starts reception through a channel for BCMCS reception at a predetermined time based on the BCMCS program table, and receives BCMCS data. The base station AN transmits a BOM (Broadcast Overhead Message) before transmitting BCMCS data and at the same time with the BCMCS broadcasting. The BOM includes information for receiving BCMCS data such as physical channel information, sector information of BCMCS data, and the like. The terminal AT is on standby for a telephone call or data communication as usual and also tries to receive BOM at periods of about 3 seconds. A reception unit performs a normal slot reception (with standby every 5 seconds) operation, and also performs another slot reception (with standby every about 3 seconds) operation for BOM. Thus, a status of the reception unit at that time is referred to as a dual slotted mode. The terminal AT starts receiving BOM transmitted from the base station AN in the dual slotted mode, performs a process (pre-process) which is needed to receive BCMCS based on the BOM data, and thereafter starts receiving BCMCS data. When there is no change in a communication state of the terminal AT during receiving BCMCS data, the terminal AT successfully completes the reception as shown in FIG. 4. However, there are cases where the communication state of the terminal AT is changed due to a usual telephone call, data communication or the like, and a channel establishment state is changed according to the change of the communication state, which affects reception of BCMCS data. Below, a particular example which affects reception of BCMCS data in the convention art will be described with reference to a drawing.